# Copyright 2019 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

cmake_minimum_required(VERSION 3.13)
if(POLICY CMP0077)
  cmake_policy(SET CMP0077 NEW)
endif()
# Allow target_link_libraries() from other directories (since 3.13):
#   https://cmake.org/cmake/help/v3.13/policy/CMP0079.html
if(POLICY CMP0079)
  cmake_policy(SET CMP0079 NEW)
endif()
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

project(iree CXX C)
set(CMAKE_C_STANDARD 11)
set(CMAKE_CXX_STANDARD 14)
set(IREE_IDE_FOLDER IREE)
set_property(GLOBAL PROPERTY USE_FOLDERS ON)

#-------------------------------------------------------------------------------
# Project component configuration
#-------------------------------------------------------------------------------

# LINT.IfChange(iree_options)
option(IREE_ENABLE_RUNTIME_TRACING "Enables instrumented runtime tracing." OFF)
option(IREE_ENABLE_MLIR "Enables MLIR/LLVM dependencies." ON)
option(IREE_ENABLE_EMITC "Enables MLIR EmitC dependencies." OFF)

option(IREE_BUILD_COMPILER "Builds the IREE compiler." ON)
option(IREE_BUILD_TESTS "Builds IREE unit tests." ON)
option(IREE_BUILD_DOCS "Builds IREE docs." OFF)
option(IREE_BUILD_SAMPLES "Builds IREE sample projects." ON)
option(IREE_BUILD_DEBUGGER "Builds the IREE debugger app." OFF)
option(IREE_BUILD_PYTHON_BINDINGS "Builds the IREE python bindings" OFF)
option(IREE_BUILD_EXPERIMENTAL "Builds experimental projects." OFF)

#TODO: Make this functional!
set(IREE_HAL_DRIVERS_TO_BUILD "all"
  CACHE STRING "Semicolon-separated list of HAL drivers to build, or \"all\"." FORCE)
set(IREE_TARGET_BACKENDS_TO_BUILD "all"
  CACHE STRING "Semicolon-separated list of target backends to build, or \"all\"." FORCE)
# LINT.ThenChange(
#   https://github.com/google/iree/tree/master/build_tools/cmake/iree_cross_compile.cmake:iree_cross_compile_options,
#   https://github.com/google/iree/tree/master/build_tools/cmake/iree_cross_compile.cmake:iree_cross_compile_invoke
# )

if(${IREE_BUILD_SAMPLES} OR ${IREE_BUILD_EXPERIMENTAL})
  set(IREE_BUILD_COMPILER ON CACHE BOOL "Build the IREE compiler for sample projects." FORCE)
endif()

if(${IREE_BUILD_COMPILER})
  set(IREE_ENABLE_MLIR ON CACHE BOOL "Enable LLVM dependencies if the IREE compiler is build." FORCE)
endif()

if (${IREE_ENABLE_MLIR})
  set(IREE_MLIR_DEP_MODE "BUNDLED" CACHE STRING "One of BUNDLED (default), DISABLED, INSTALLED")
endif()

if(${IREE_ENABLE_EMITC})
  if(NOT ${IREE_ENABLE_MLIR})
    message(FATAL_ERROR "Enabling EmitC requires setting IREE_ENABLE_MLIR to ON.")
  endif()

  string(TOUPPER "${IREE_MLIR_DEP_MODE}" uppercase_IREE_MLIR_DEP_MODE)
  if(NOT uppercase_IREE_MLIR_DEP_MODE MATCHES "^(BUNDLED|INSTALLED)$")
    message(FATAL_ERROR "Enabling EmitC requires IREE_MLIR_DEP_MODE set to BUNDELED or INSTALLED.")
  endif()
endif()

#-------------------------------------------------------------------------------
# Target and backend configuration
#-------------------------------------------------------------------------------

# List of all HAL drivers to be built by default:
set(IREE_ALL_HAL_DRIVERS
  DyLib
  LLVM
  Vulkan
  VMLA
)

if( IREE_HAL_DRIVERS_TO_BUILD STREQUAL "all" )
  set( IREE_HAL_DRIVERS_TO_BUILD ${IREE_ALL_HAL_DRIVERS} )
endif()
message(STATUS "Building HAL drivers ${IREE_HAL_DRIVERS_TO_BUILD}")

# Default every IREE_HAL_DRIVER_* to OFF
foreach(_backend ${IREE_ALL_HAL_DRIVERS})
  string(TOUPPER "${_backend}" uppercase_backend)
  set(IREE_HAL_DRIVER_${uppercase_backend} OFF CACHE BOOL "" FORCE)
endforeach()

# Set IREE_HAL_DRIVER_* based on configuration
foreach(_backend ${IREE_HAL_DRIVERS_TO_BUILD})
  string(TOUPPER "${_backend}" uppercase_backend)
  set(IREE_HAL_DRIVER_${uppercase_backend} ON CACHE BOOL "" FORCE)
endforeach()


# List of all target backends to be built by default:
set(IREE_ALL_TARGET_BACKENDS
  # TODO(scotttodd): LLVMAOT
  LLVMIR
  Vulkan_SPIRV
  VMLA
)

if( IREE_TARGET_BACKENDS_TO_BUILD STREQUAL "all" )
  set( IREE_TARGET_BACKENDS_TO_BUILD ${IREE_ALL_TARGET_BACKENDS} )
endif()
message(STATUS "Building target backends ${IREE_TARGET_BACKENDS_TO_BUILD}")

# Default every IREE_TARGET_BACKEND_* to OFF
foreach(_backend ${IREE_ALL_TARGET_BACKENDS})
  string(TOUPPER "${_backend}" uppercase_backend)
  set(IREE_TARGET_BACKEND_${uppercase_backend} OFF CACHE BOOL "" FORCE)
endforeach()

# Set IREE_TARGET_BACKEND_* based on configuration
foreach(_backend ${IREE_TARGET_BACKENDS_TO_BUILD})
  string(TOUPPER "${_backend}" uppercase_backend)
  set(IREE_TARGET_BACKEND_${uppercase_backend} ON CACHE BOOL "" FORCE)
endforeach()

list(APPEND CMAKE_MODULE_PATH
  ${CMAKE_CURRENT_LIST_DIR}/build_tools/cmake/
  ${CMAKE_CURRENT_LIST_DIR}/bindings/python/build_tools/cmake/
  ${CMAKE_CURRENT_LIST_DIR}/third_party/abseil-cpp/absl/copts/
)

#-------------------------------------------------------------------------------
# Cross compiling configuration
#-------------------------------------------------------------------------------

if(CMAKE_CROSSCOMPILING)
  if(CMAKE_HOST_SYSTEM_NAME STREQUAL Windows)
    message(FATAL_ERROR "Cross compilation with Windows host system is not supported yet")
  endif()

  message(STATUS "Detected cross compilation mode; configuring IREE on host...")

  # C/C++ compilers for host compilation.
  # Note: we need to explicitly set this because IREE does not work well with
  # GCC at the moment: https://github.com/google/iree/issues/1269
  set(IREE_HOST_C_COMPILER "$ENV{IREE_HOST_C_COMPILER}" CACHE FILEPATH "C compiler for host compilation")
  set(IREE_HOST_CXX_COMPILER "$ENV{IREE_HOST_CXX_COMPILER}" CACHE FILEPATH "C++ compiler for host compilation")

  # Master configuration for the binary directory containing all artifacts
  # compiled for host.
  if(NOT IREE_HOST_BINARY_ROOT)
    set(IREE_HOST_BINARY_ROOT "${CMAKE_CURRENT_BINARY_DIR}/host" CACHE FILEPATH "directory containing host artifacts")
  endif()

  set(IREE_HOST_BUILD_COMPILER ON) # For iree-translate
  set(IREE_HOST_ENABLE_LLVM ON)    # For iree-tblgen

  # Set the host build directory for LLVM to our directory. Otherwise it will
  # follow its own convention.
  set(LLVM_NATIVE_BUILD "${IREE_HOST_BINARY_ROOT}/third_party/llvm-project/llvm")

  include(iree_cross_compile)

  # Use another CMake invocation to configure a build for host.
  iree_create_configuration(HOST)

  message(STATUS "Done configuring IREE on host in ${IREE_HOST_BINARY_ROOT}")
endif()

#-------------------------------------------------------------------------------
# IREE utility definitions
#-------------------------------------------------------------------------------

include(iree_macros)
include(iree_copts)
include(iree_cc_binary)
include(iree_cc_library)
include(iree_cc_test)
include(iree_tablegen_library)
include(iree_tablegen_doc)
include(iree_cc_embed_data)
include(iree_bytecode_module)
include(iree_pybind_cc_library)
include(iree_py_extension)
include(iree_py_library)
include(iree_py_test)
include(iree_lit_test)
include(iree_add_all_subdirs)
include(iree_check_test)

set(DEFAULT_CMAKE_BUILD_TYPE "Release")
if (NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
  message(STATUS "No build type selected, default to ${DEFAULT_CMAKE_BUILD_TYPE}")
  set(CMAKE_BUILD_TYPE "${DEFAULT_CMAKE_BUILD_TYPE}" CACHE STRING "Build type (default ${DEFAULT_CMAKE_BUILD_TYPE})" FORCE)
endif()

set(CMAKE_POSITION_INDEPENDENT_CODE TRUE)

#-------------------------------------------------------------------------------
# IREE compilation toolchain configuration
#-------------------------------------------------------------------------------

# Enable using lld as the linker for C/C++ targets. This affects IREE and all
# dependency projects.
option(IREE_ENABLE_LLD "Use lld when linking" OFF)

string(JOIN " " CMAKE_CXX_FLAGS ${IREE_DEFAULT_COPTS})

set(CMAKE_CXX_FLAGS_FASTBUILD "-gmlt" CACHE STRING "Flags used by the C++ compiler during fast builds." FORCE)
set(CMAKE_C_FLAGS_FASTBUILD "-gmlt" CACHE STRING "Flags used by the C compiler during fast builds." FORCE)
set(CMAKE_EXE_LINKER_FLAGS_FASTBUILD "-Wl,-S" CACHE STRING "Flags used for linking binaries during fast builds." FORCE)
set(CMAKE_SHARED_LINKER_FLAGS_FASTBUILD "-Wl,-S" CACHE STRING "Flags used by the shared libraries linker binaries during fast builds." FORCE)
mark_as_advanced(
  CMAKE_CXX_FLAGS_FASTBUILD
  CMAKE_C_FLAGS_FASTBUILD
  CMAKE_EXE_LINKER_FLAGS_FASTBUILD
  CMAKE_SHARED_LINKER_FLAGS_FASTBUILD
)

include(iree_setup_toolchain)

#-------------------------------------------------------------------------------
# MLIR/LLVM Dependency
# We treat the LLVM dependency specially because we support several different
# ways to use it:
#   - Bundled (default): a source dependency directly on the 
#     third_party/llvm-project submodule.
#   - External: An external (source or installed) dependency on LLVM.
#   - Provided: When IREE is used as a sub-project, it is assumed that the LLVM
#     dependency is added prior to including this configuration.
#-------------------------------------------------------------------------------


# Adds bundled projects that must be included after the LLVM directory has
# been added and within the scope of its settings (i.e. build type override, 
# etc).
function(add_bundled_mlir_dependent_projects)
  if(${IREE_ENABLE_EMITC})
  add_subdirectory(third_party/mlir-emitc EXCLUDE_FROM_ALL)
  endif()
endfunction()

function(add_iree_mlir_src_dep llvm_monorepo_path)
  # If CMAKE_BUILD_TYPE is FastBuild, set to Debug for llvm
  set(_CMAKE_BUILD_TYPE "${CMAKE_BUILD_TYPE}")
  string(TOUPPER "${CMAKE_BUILD_TYPE}" uppercase_CMAKE_BUILD_TYPE)
  if(NOT uppercase_CMAKE_BUILD_TYPE MATCHES "^(DEBUG|RELEASE|RELWITHDEBINFO|MINSIZEREL)$")
    set(CMAKE_BUILD_TYPE "Debug")
  endif()

  add_subdirectory("${llvm_monorepo_path}/llvm" "third_party/llvm-project/llvm" EXCLUDE_FROM_ALL)

  # Reset CMAKE_BUILD_TYPE to its previous setting
  set(CMAKE_BUILD_TYPE "${_CMAKE_BUILD_TYPE}" CACHE STRING "Build type (default ${DEFAULT_CMAKE_BUILD_TYPE})" FORCE)
endfunction()

if(${IREE_ENABLE_MLIR})
  if(${IREE_MLIR_DEP_MODE} STREQUAL "DISABLED")
    message(STATUS "Not adding MLIR/LLVM dep due to IREE_MLIR_DEP_MODE=DISABLED")
  elseif(${IREE_MLIR_DEP_MODE} STREQUAL "BUNDLED")
    # TODO: See iree_copts.cmake where it sets include directories for this
    # case. This should be cleaned up to be all in one place or the other for
    # all modes.
    message(STATUS "Adding bundled LLVM source dependency")
    add_iree_mlir_src_dep("third_party/llvm-project")
  elseif(${IREE_MLIR_DEP_MODE} STREQUAL "INSTALLED")
    message(STATUS "Looking for installed MLIR/LLVM packages (configure with MLIR_DIR variable)")
    find_package(MLIR REQUIRED CONFIG)
    message(STATUS "Using MLIRConfig.cmake in: ${MLIR_DIR}")
    message(STATUS "Using LLVMConfig.cmake in: ${LLVM_DIR}")
    list(APPEND CMAKE_MODULE_PATH "${MLIR_CMAKE_DIR}")
    list(APPEND CMAKE_MODULE_PATH "${LLVM_CMAKE_DIR}")
    include(TableGen)
    include(AddLLVM)
    include(AddMLIR)
    include(HandleLLVMOptions)

    # Add include/link directories
    include_directories(${LLVM_INCLUDE_DIRS})
    include_directories(${MLIR_INCLUDE_DIRS})
    link_directories(${LLVM_BUILD_LIBRARY_DIR})
    add_definitions(${LLVM_DEFINITIONS})
  else()
    message(FATAL "Unsupported IREE_MLIR_DEP_MODE=${IREE_MLIR_DEP_MODE}")
  endif()

  include(external_tablegen_library)
  add_bundled_mlir_dependent_projects()
endif()


#-------------------------------------------------------------------------------
# Non-LLVM Dependencies
#-------------------------------------------------------------------------------

# Use the (deprecated) FindPythonInterp/FindPythonLibs functions before
# any of our dependencies do. See
# https://pybind11.readthedocs.io/en/stable/faq.html#inconsistent-detection-of-python-version-in-cmake-and-pybind11
# If one dependency finds Python 2 (the default),
# any others that try to find Python 3 will fail.
# (Also come on, it's $CURRENT_YEAR - please just use Python 3 already.)
if(${IREE_BUILD_COMPILER} OR ${IREE_BUILD_PYTHON_BINDINGS})
  find_package(PythonInterp 3 REQUIRED)
endif()
if(${IREE_BUILD_PYTHON_BINDINGS})
  find_package(PythonLibs 3 REQUIRED)
endif()

list(APPEND CMAKE_MODULE_PATH
  ${CMAKE_CURRENT_LIST_DIR}/third_party/flatbuffers/CMake/
)

include(external_cc_library)
include(flatbuffer_cc_library)

add_subdirectory(build_tools/third_party/ruy EXCLUDE_FROM_ALL)

add_subdirectory(third_party/googletest EXCLUDE_FROM_ALL)
add_subdirectory(third_party/abseil-cpp EXCLUDE_FROM_ALL)
add_subdirectory(third_party/flatbuffers EXCLUDE_FROM_ALL)
add_subdirectory(third_party/vulkan_headers EXCLUDE_FROM_ALL)
add_subdirectory(third_party/vulkan_extensionlayer EXCLUDE_FROM_ALL)
add_subdirectory(build_tools/third_party/renderdoc_api EXCLUDE_FROM_ALL)
add_subdirectory(build_tools/third_party/vulkan_extensionlayer EXCLUDE_FROM_ALL)

if(CMAKE_CROSSCOMPILING)
  # We need flatc to generate some source code. When cross-compiling, we need
  # to make sure the flatc binary is configured under host environment.
  iree_declare_host_excutable(flatc BUILDONLY)

  # Set the FLATBUFFERS_FLATC_EXECUTABLE. It controls where to find the flatc
  # binary in BuildFlatBuffers().
  iree_get_executable_path(FLATBUFFERS_FLATC_EXECUTABLE flatc)

  # Add a custom target to copy the flatc to the binary directory.
  add_custom_target(iree_host_flatc
    COMMAND "${CMAKE_COMMAND}" -E copy_if_different
      "${IREE_HOST_BINARY_ROOT}/third_party/flatbuffers/flatc" "${IREE_HOST_BINARY_ROOT}/bin"
    DEPENDS iree_host_build_flatc
    COMMENT "Installing host flatc..."
  )
endif()

if(${IREE_BUILD_COMPILER})
  add_subdirectory(build_tools/third_party/tensorflow/tensorflow/compiler/mlir/xla EXCLUDE_FROM_ALL)
endif()

if(${IREE_BUILD_DEBUGGER} OR ${IREE_BUILD_SAMPLES})
  # sdl2 logs are spammy - change log level while adding
  function(include_sdl2)
    set(CMAKE_MESSAGE_LOG_LEVEL "WARNING")
    add_subdirectory(third_party/sdl2 EXCLUDE_FROM_ALL)
  endfunction()
  include_sdl2()

  add_subdirectory(build_tools/third_party/dear_imgui EXCLUDE_FROM_ALL)
endif()

if(${IREE_BUILD_TESTS})
  add_subdirectory(third_party/benchmark EXCLUDE_FROM_ALL)
  enable_testing(iree)
endif()

if(${IREE_BUILD_PYTHON_BINDINGS})
  add_subdirectory(third_party/pybind11 EXCLUDE_FROM_ALL)
endif()

#-------------------------------------------------------------------------------
# IREE top-level targets
#-------------------------------------------------------------------------------

if(${IREE_BUILD_DOCS})
  # Add a top-level custom target to drive generating all documentation.
  # Register it to the default target given that IREE_BUILD_DOCS is explicitly
  # requested.
  add_custom_target(iree-doc ALL)
endif()

#-------------------------------------------------------------------------------
# IREE top-level libraries
#-------------------------------------------------------------------------------

add_subdirectory(build_tools/embed_data/)

add_subdirectory(iree/base)
add_subdirectory(iree/hal)
add_subdirectory(iree/modules)
add_subdirectory(iree/schemas)
add_subdirectory(iree/testing)
add_subdirectory(iree/test)

if(${IREE_ENABLE_MLIR})
  # The VM requires LLVM to build its op definitions.
  add_subdirectory(iree/vm)
endif()

if(${IREE_BUILD_COMPILER})
  add_subdirectory(iree/compiler)
elseif(${IREE_ENABLE_MLIR})
  # If not building the compiler, tablegen is still needed
  # to generate vm ops so deep include it only.
  add_subdirectory(iree/compiler/Dialect/IREE/Tools)
  add_subdirectory(iree/compiler/Dialect/VM/Tools)
endif()

if(${IREE_BUILD_PYTHON_BINDINGS})
  add_subdirectory(bindings/python)
endif()

add_subdirectory(iree/tools)

if(${IREE_BUILD_SAMPLES})
  add_subdirectory(iree/samples)
endif()

if(${IREE_BUILD_EXPERIMENTAL})
  add_subdirectory(experimental)
endif()

# Note: this must be called after all libraries have been declared.
iree_complete_binary_link_options()
if(${IREE_BUILD_PYTHON_BINDINGS})
  iree_complete_py_extension_link_options()
endif()

set(IREE_PUBLIC_INCLUDE_DIRS "${IREE_COMMON_INCLUDE_DIRS}"
    CACHE INTERNAL "IREE: Include Directories" FORCE)